Billet mold



May 1937- i ,F. c. ELDER 1 2,080,961

BILLET MOLD Filed Oct. 22, 1935 s Sheets-Sheet 1 fl/N7 C. ELDER,

'liweizior."

May 18, 1937.

F. c. ELDER" BILLET MOLD 3 Sheets-Sheet 2 lnvenior:

C ELDER Filed Oct. 22, 1935 FA/NT Ma 'ls, 1937.

F. c. ELDER BILLET MOLD Filed 0ct.'22, 1935 s Sheets-Sheet s nim.

nmrp

fZ/NT 6154058,

Patented May 18, 1937 UNITED STATES PATENT OFFICE BILLET MOLD Application October 22, 1935, Serial No. 46,186

1 Claim.

This invention relates't-o casting apparatus, and more particularly to billet molds of the type shown and described in my Patent No. 1,945,887, dated February 6, 1934.

In the formation of billets, it has heretofor been the practice to cast molten metal into relatively large ingots, or blooms, and to thereafter reduce the ingots by rolling or working down to billet size. In the production of articles from billets, it required much preliminary expenditure of time and money to first obtain the billets, as ggzzin'ibed above, before actual fabrication could My prior patent mentioned sought to obviate this needless expense. It contemplates the provision of a mold having a plurality of metalforming cavities therein, instead of the usual single opening, whereby a number of bars of metal or billets could be poured simultaneously" in place of a large unitary ingot.

It was originally considered desirable to pro vide such a. compound mold in such form as would externally simulate'an ordinary ingot mold, but

. inside would differentiate therefrom in that it would have a plurality of molding cavities in spaced relation extending longitudinally through the body. Such openings should preferably be even in number, of a uniform size, and symmetrically arranged in spaced, parallel relationship.

It was found, however, that the manufacture of such .a mold was exceedingly difiicult and was,-

in fact, commercially impracticable to produce due to the large number in each .lot'that had to be scrapped. v

. The difficulty .was encountered when the sand molds and cores, used to form the billet molds, were found to be deleteriously aifected'by the heat of the moltenmetal being cast to formthem.

The central billet cavities, as well as the smaller cavities, are formed by sand core members reenforced by metal rods. Apparently the intense heat of the cast, due to the excessive'quantity of metal present to form the partitions for such a compound mold, sometimes causes the cores to warp or be distorted. from a true axis, whereby the central cavities areformed out of alinement.

,This condition became manifest when billets were cast in such molds and an efl'ort made to strip them in the usual way. Due to the imperfect die cavities they were lodged so fast as'to be unremovable.

This situation was remedied by the adoption of the structure, shown in my prior patent referred to hereinbefore. Instead of partitioning the entire mold into a plurality of billet forming remold formed in the manner last described, only the small billets of uniform siz'eare utilizable, and the large billet or ingot that forms in the central pouring recess has to be worked down to billet size or returned to the furnace as scrap.

' This slows up production and entails delays and wastage inconsistent with economical practice.

Hence, it is an object of the present invention to provide a compound mold ,of the cmss described wherein all metal-forming recesses will be of uniform size, but which may be made so that such recesses are straight and true throughout their length to permit of readily stripping all billets therefrom.

Other objects will become apparent by referring to the accompanying specification and drawings.

' In the drawings:

Figure l is a top plan of the composite mold of the invention.

Figure 2 is a view similar to Figure 1 but showing part of the apparatus removed.

Figure 3 is a plan of the part of the apparatus which has been removed in Figure 2.

Figure 4 is a longitudinal sectional view, taken on the line IV-IV of Figure 1.

Figure 5 is .a perspective view of the device illustrated with the central portion thereof partially withdrawn.

Figure 61s a plan of the sprue plate, or removable mold bottom, which is shown in section in Figure 4.

Figure 'l is a detailed section of the mold showing the tapered surfaces of the inner and outer mold members.

'consists essentially of three main parts, a main body portion A, a central insert B, and a sprue plate or pouring base C.

The element A of the mold is formed with a central opening 2 and a plurality of smaller openings.3 of equal size. The central opening 2 is of the proper size and shape to accommodate the central insert B.

member from sliding or dropping out when positioned therein.

Another construction for positioning the central insert B in the memberA may be employed to eliminate lugs and notches 6. This construction contemplates slightly tapering the outside surfaces of the insert B so that it will be slightly.

smaller in cross-sectional area at its bottom than at its top. The opening 2 in the member A will be formed with a complementary taper, whereby the insert will fit snugly in the opening 2. The taper of the-mold sections is clearly indicated at 2 in Figure 7 of the drawings.

The taper in such a'construction should extend as in an inverted cone so that when the billets are stripped from the mold, which is always accomplished by the application of downward pressure, the insert will not be dislodged from its position in the member A.

Inasmuch as ingot molds that are adapted for use with a sprue plate, such as that shown in Figures 4 and 6, all have to be machine-finished across their 'bottom surfaces to insure a seal engagement with the sprue plate, the insert B, when the taper construction -is employed, may be made slightly longer thanthe member A so that when it is wedged in place therein a portion of it will project beyond the bottom thereof, which-may be removed in the subsequent machining operation: Such construction would obviously facilitate the production of such molds by reducing the care and precision required in the molding of the insert to exact dimensions.

The two'mold elementsA andB may readily be molded separately without causing the sand cores employed in their formation to warp or distort out of alinement. This is because the bulk of "metal that goes into each mold element is sufliciently small so as not to oflfer an excess of either heat or weight upon the forming cores to deleteriously aifect them. Whereas if the two elementsA and B were castintegrally, the diillculties discussed hereinbefore would arise.

After the elements A and B are formed, the element B is inserted in the opening 2 in the element A to constitute a composite unitary mold. It may then be retained therein merely by its ownweight,- or itmay be ,welded or otherwise secured in any desired manner.

Instead of casting the elements A and B in two separate molds and later assembling them together, the central portion, described hereinbefore as insert B, may be poured directly into the central opening 2 of element A after the latter has been formed. In such case, mold cores for forming the openings 4 are introduced into opening 2 and molten metal is poured therein to form the central portion 13, which becomes fused to the walls of the opening 2 and thereby is integrally and permanently united to the element A.

The compound mold thus formed is now ready for association with the sprue plate, or mold bottom C, shown in planviewin Figure 6. The assembly is illustrated in section in Figure 4.

In operation, the entire mold, constituting elements A, B and C, is assembledas shown in Figure 4. The metal to be cast into billets is poured through any of the openings 3 or 4, but preferably the latter. The fluid metal descends to the bottom of the opening through which it is being introduced to the mold, and into the gutters I of the sprue plate C. The gutters 1 direct .the fluid metal to the bottoms of the remaining openings 34 into which it flows; and begins to rise. When the fluid metal reaches the top of the openings 3-4 the cast is finished. After the metal has set, the mold is removedfrom the sprue plate C and the billets are st ipped therefrom. The stringers connecting the various billets, which were formed by the gutters 1, are then cut oil by a torch or any suitable means. Thus, -a plurality of billets are formed in one operation, and substantially the entire cast is usable.

While I have shown and described one specific embodiment of my invention, it will be understood that I do not wish to be limited exactly thereto, since various modifications may be made without departing from the scope of my invention, as defined in the following claim.

I claim: 7 A unitary mold comprising a composite mold body provided with an outer elongated cast metal mold member, said member having a plurality of separate longitudinal parallel mold cavities extending therethrough, one of said cavities being substantially larger in transverse dimensions than the remainder thereof, an inner cast metal mold member positioned in'said larger cavity, said inner cast mold having longitudinal parallel mold cavities extending therethrough, each of the latter being equal in volume to each of the mold cavities of said outer mold member.

FLINT C. ELDER. 

